1 files changed, 114 insertions, 0 deletions
diff --git a/third_party/rust/proc-macro-hack/src/quote.rs b/third_party/rust/proc-macro-hack/src/quote.rs
new file mode 100644
index 0000000000..a3d648d1a4
--- /dev/null
+++ b/third_party/rust/proc-macro-hack/src/quote.rs
@@ -0,0 +1,114 @@
+use proc_macro::{Ident, TokenStream, TokenTree};
+use std::iter;
+
+macro_rules! quote {
+    () => {
+        ::proc_macro::TokenStream::new()
+    };
+    ($($tt:tt)*) => {{
+        let mut tokens = ::proc_macro::TokenStream::new();
+        quote_each_token!(tokens $($tt)*);
+        tokens
+    }};
+}
+
+macro_rules! quote_each_token {
+    ($tokens:ident # $var:ident $($rest:tt)*) => {
+        $crate::quote::Tokens::extend(&mut $tokens, &$var);
+        quote_each_token!($tokens $($rest)*);
+    };
+    ($tokens:ident $ident:ident $($rest:tt)*) => {
+        <::proc_macro::TokenStream as ::std::iter::Extend<_>>::extend(
+            &mut $tokens,
+            ::std::iter::once(
+                ::proc_macro::TokenTree::Ident(
+                    ::proc_macro::Ident::new(
+                        stringify!($ident),
+                        ::proc_macro::Span::call_site(),
+                    ),
+                ),
+            ),
+        );
+        quote_each_token!($tokens $($rest)*);
+    };
+    ($tokens:ident ( $($inner:tt)* ) $($rest:tt)*) => {
+        <::proc_macro::TokenStream as ::std::iter::Extend<_>>::extend(
+            &mut $tokens,
+            ::std::iter::once(
+                ::proc_macro::TokenTree::Group(
+                    ::proc_macro::Group::new(
+                        ::proc_macro::Delimiter::Parenthesis,
+                        quote!($($inner)*),
+                    ),
+                ),
+            ),
+        );
+        quote_each_token!($tokens $($rest)*);
+    };
+    ($tokens:ident [ $($inner:tt)* ] $($rest:tt)*) => {
+        <::proc_macro::TokenStream as ::std::iter::Extend<_>>::extend(
+            &mut $tokens,
+            ::std::iter::once(
+                ::proc_macro::TokenTree::Group(
+                    ::proc_macro::Group::new(
+                        ::proc_macro::Delimiter::Bracket,
+                        quote!($($inner)*),
+                    ),
+                ),
+            ),
+        );
+        quote_each_token!($tokens $($rest)*);
+    };
+    ($tokens:ident { $($inner:tt)* } $($rest:tt)*) => {
+        <::proc_macro::TokenStream as ::std::iter::Extend<_>>::extend(
+            &mut $tokens,
+            ::std::iter::once(
+                ::proc_macro::TokenTree::Group(
+                    ::proc_macro::Group::new(
+                        ::proc_macro::Delimiter::Brace,
+                        quote!($($inner)*),
+                    ),
+                ),
+            ),
+        );
+        quote_each_token!($tokens $($rest)*);
+    };
+    ($tokens:ident $punct:tt $($rest:tt)*) => {
+        <::proc_macro::TokenStream as ::std::iter::Extend<_>>::extend(
+            &mut $tokens,
+            stringify!($punct).parse::<::proc_macro::TokenStream>(),
+        );
+        quote_each_token!($tokens $($rest)*);
+    };
+    ($tokens:ident) => {};
+}
+
+pub trait Tokens {
+    fn extend(tokens: &mut TokenStream, var: &Self);
+}
+
+impl Tokens for Ident {
+    fn extend(tokens: &mut TokenStream, var: &Self) {
+        tokens.extend(iter::once(TokenTree::Ident(var.clone())));
+    }
+}
+
+impl Tokens for TokenStream {
+    fn extend(tokens: &mut TokenStream, var: &Self) {
+        tokens.extend(var.clone());
+    }
+}
+
+impl<T: Tokens> Tokens for Option<T> {
+    fn extend(tokens: &mut TokenStream, var: &Self) {
+        if let Some(var) = var {
+            T::extend(tokens, var);
+        }
+    }
+}
+
+impl<T: Tokens> Tokens for &T {
+    fn extend(tokens: &mut TokenStream, var: &Self) {
+        T::extend(tokens, var);
+    }
+}